If you’ve ever felt a rush of intense emotion, then you’ve probably also experienced the crash that comes when those emotions gradually become less strong. Although we usually think of exhaustion (精疲力竭) in physical terms, it can also be mental. One of the contributors to mental exhaustion is high-intensity emotions. Too many of these high-intensity emotions, whether they are positive or negative, can lead to burnout.

Psychologists divide emotions into two dimensions, which includes high and low intensity, as well as positive and negative. High-intensity positive emotions include excitement or elation, while low-intensity positive emotions include calmness, or contentment. When it comes to negative emotions, high-intensity emotions include anger, anxiety, and fear, while low-intensity emotions include sadness, boredom, and tiredness.

It’s easy to see how high-intensity negative emotions like anger can be exhausting. What we don’t think about as much is the fact that high intensity positive emotions are also exhausting, although in a way that feels very different.

Excitement, even when it is fun, involves what psychologists call “physiological arousal”-- activation of our sympathetic system. High-intensity positive emotions involve the same physiological arousal as high-intensity negative emotions. Our heart rate increases, and our sweat glands (腺) activate. Because it activates the body’s stress response, excitement can deplete our system when sustained over longer periods. In other words, high intensity -- whether it’s from negative states or positive states- exhausts the body.

About 15-20% of people are thought to be highly sensitive. As they cycle through the highs and lows of life, the increased amount of intensity leaves them more exhausted than others.

This isn’t to say that we should never feel intense emotions. Emotional variety is an essential aspect of life, one that adds a depth and richness that we need. However, what we need to be mindful of is balance. There will be the exciting days, as well as the days when stress and anxiety are what push you through the tough times, but there are other, lower-intensity emotions that will serve us well in many other situations.

A research lab called DeepMind has created an artificial intelligence (AI) program which has largely solved a complicated puzzle that has challenged scientists for 50 years. The success could lead to huge advances in health care. The new puzzle solved by DeepMind is “protein folding”.

Proteins make up the bodies of all living things. Scientists have found over 200 million different kinds of proteins, but they don't know what shape most of them take.

The shape of protein controls how it acts. Based on their shapes, some proteins join together like puzzle pieces. In living things, proteins serve many purposes. Some proteins are used for building, some far carrying messages, others for causing chemical reactions. Knowing how these proteins are formed is important. The shape can make the difference between something that's helpful and something that can make you sick. Many medicines work by targeting the shape of a protein that is causing the illness.

But untangling the secrets behind how proteins fold has been slow and difficult. In some cases, it has taken years for scientists to learn how one simple protein folds. Now DeepMind's Al has shown that it can often do that same job in just a few days.

To accomplish this, the scientists created a program called AlphaFold using an Al method known as “Deep Learning”. In deep learning, computer programs sort deeply through huge amounts of information» allowing them to find patterns that humans are often unable to notice. These patterns can then be applied in new and surprising ways.

AlphaFold was trained by feeding it information about the make up of 170,000 proteins and how they folded. Once AlphaFold was trained, DeepMind entered it in a contest for solving protein folding challenges. AlphaFold did much better than other computer systems. And on two-thirds of the proteins, it did about as well as real scientists do in the lab. Though AlphaFold can figure out the shape for wide variety of proteins, it’s not perfect. It's likely that there will be many proteins that AlphaFold, with its current abilities, won't be able to handle.

Across the developing world, homeowners, farmers, and businesses are turning to cheap, secondhand solar to fill power gaps left by governments and utilities. To meet that demand, businesses ranging from individual sellers on Facebook to specialized brokerages are getting into the trade.

Earlier this month, Marubeni Corp., one of Japan’s largest trading houses, announced that it’s establishing a blockchain-based market for used solar panels（太阳能板）. Collectively, these businesses will likely play a crucial role in bringing renewable energy to the world’s emerging markets（新兴市场）—and keeping high-tech waste out of the trash.

In 2016, the International Renewable Energy Agency estimated that as much as 78 million tons of solar-panel waste will be generated by 2050. That’s almost certainly an undercount. Over the past decade, falling prices and improved efficiency in newer models have offered a strong incentive to replace solar panels earlier than their intended lifespan. By one estimate, those upgrades could lead to 50 times more waste than the agency has predicted within five years.

In developed countries, recycling-not reuse and resale-tends to be the natural response to managing such waste. But there are two problems with recycling unwanted solar panels. First, doing so is far costlier than simply burying them. Second, waste solar panels often aren’t waste, they’re just degraded by time in the sun or less efficient than newer models. They may not be good enough for San Francisco homeowners and advanced utilities, but they work perfectly well for anyone in a sunny climate in need of stable, off-grid（离输电网）power who doesn’t want to pay full price.

That’s potentially a huge market. Between 2010 and 2019, the number of people living without electricity declined from 1.2 billion to 759 million in developing countries. Some of that gap was closed by new power lines and other transmission facilities. But most of it was achieved by installing used solar panels to power a village, farm or even a single home. As of last year, 420 million people got their electricity from off-grid solar systems. By 2030, according to the World Bank, that number could nearly double.